Conventionally when electrical generating components such as turbines, generators, converters, hydraulic oils, and the like exceed a maximum thermal parameter, the electrical generating control system will shut down the electrical generator until the thermal parameter is within the operating range before restarting. Some control systems will operate an electrical generating component at a reduced output, otherwise known as de-rating, until the thermal state of the electrical generating component is within the operating range.
In the field of turbines, many turbines employ liquid or air transfer systems, which use some of the electrical energy generated to keep an electrical generating component cool. This results in a net loss of energy production while mitigating the stress on thermally sensitive electrical generating components. Other turbines avoid the added expense and energy usage of a cooling system by de-rating or shutting down the turbine when electrical generating components have reached the limits of a thermal parameter.
Shutting down the turbine until the thermally sensitive electrical generating components have cooled ceases power production and eliminates stress on thermally sensitive electrical generating components. A de-rated turbine is limited at the upper regions of its power production range. De-rating a turbine to control the temperature of electrical generating components, results in a reduction of the rated power production, while mitigating the stress on the thermally sensitive components.
A sinusoidal alternating voltage applied to a purely resistive load provides an alternating current that is in phase with the voltage. Commonly, there is a reactive component and the system possess capacitance, inductance or both. Apparent Power is the absolute value of the combined power produced, real-Power (measured in Watts (W) and Reactive power, measured in Volt-Ampere-Reactive (VAR). Conventionally, capacitors are considered to generate reactive power and inductors to consume it. Capacitors or inductors are inserted in a circuit to consume or generate reactive power.